Photovoltaics-organics-operation

OECD Organisation for Economic Co-operation and Development OPV organic (polymer-based) photovoltaic... 

Physical Properties. A photovoltaic device must withstand exposure to the environmental conditions encountered In the collection of solar energy. Including exposure to ultraviolet and visible radiation and operating temperatures up to 80°C. No organic polymer material which can meet these conditions - and which has suitable photovoltaic properties - has yet been Identified. Polyacrylonitrile has emerged as an Interesting candidate material because It can withstand these environmental conditions, and may have the semiconducting properties required for a photovoltaic device. 

The operation and physics of optoelectronic devices based on conjugated molecules such as light-emitting diodes (LEDs) and photovoltaic diodes, where organic thin films are sandwiched between different electrodes, is critically influenced by the barriers at electrode/semiconductor interfaces and by the electric fields present within the different functional layers of the devices. 

Working principles of organic solar cells are well described in a recent review and some monographs. More or less all types of organic solar cells described above comprise two components in the photoactive layer. One component serves as electron donor, whereas the other works as electron acceptor. Absorption of photons by the active layer components results in the electron transfer from donor to acceptor. This process called photoinduced charge transfer is a fundamental principle of operation of all known organic photovoltaic devices as well as the natural photosynthetic systems. In many cases, donor material is capable of efficient p-type transport and therefore can be called as p-type organic semiconductor. At the same time, electron acceptor material is denoted as n-type semiconductor in many cases. 

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